1. Field of the Invention
The present invention relates to wireless communication.
2. Description of Related Art
The achieved end-to-end performance of data applications is greatly influenced by the underlying transport control protocol. FIG. 1 illustrates a prior art network architecture for communicating internet protocol (IP) data packets from one wireless unit to another wireless unit where both the wireless units are located in the same cell and served by the same base station. As shown, a sending wireless unit 10 fragments each IP data packet into, generally, smaller radio link protocol (RLP) data frames. The sending wireless unit 10 transmits the RLP data frames.
A base station 20 receives the RLP data frames, and sends the RLP data frames to a packet data serving node (PDSN) 30 over radio access and backhaul networks 25. The PDSN 30 assembles the RLP data frames into IP data packets. As is known, the IP data packet includes an IP data packet header, and the IP data packet header includes the destination address of the IP data packet. Having assembled the IP data packet, the PDSN 30 may determine the destination of the IP data packet from the destination address in the IP data packet header. The PDSN 30 then refragments the IP data packet into RLP data frames. Based on the destination address of the IP data packet, the PDSN 30 sends the re-fragmented RLP data frames to the base station serving the, for example, wireless unit identified by the destination address. In this example, the destination wireless unit is the receiving wireless unit 15 served by the base station 20, which is also serving the sending wireless unit 10. As a result, the re-fragmented RLP data frames are sent back to the base station 20 from which they originally came. Besides sending the RLP data frames over the backhaul network 25 to the base station 20, the PDSN 30 also sends an indication of the destination of the RLP data frames.
Accordingly, based on the destination information received from the PDSN 30 for the RLP data frames received from the PDSN 30, the base station 20 transmits the RLP data frames to the receiving wireless unit 15. The receiving wireless unit 15 then reassembles the RLP data frames into IP data packets, and processes them.
This fragmentation of IP data packets and the aggregation of lower layer frames into IP data packets adds significantly and unnecessarily to the end-to-end delay along with the transmission delay and the processing delay at the different network entities. Retransmissions due to buffer overflow and lost packets further inflate the round trip time of IP data packets between the sending and the receiving wireless units.